Means of extruding metal tubes



May 24, 1932. J W. LEIGHTON I 1,859,707

MEANS OF EXTRUDiNG 'METAL' .IUBES Filed May 29, 1931 Patented May 24, 1932 UNITED STATES JOHN WYCLII'IE LEIGHTON, O! 201'! HURON, X10310 MEANS OI EXTBUDING METAL TUBES Application and m 29, 1931. Serial Io. 540.900.

saving of time and material and to accom-J plish these results by means of a slmplev mechanism or tool.

The art of producing metal tubes by punch 10 ress methods has, up to the present time,v

een limited to the distance the unchescan be separated from the die as t e extruded tubes retain a flange at the upper end and the tube has to be removed from the upper side 15 of the die by a knockout operation.

The principal feature of this invention consists in the novel method and means whereby the flange is removed from the tube within the die permitting the tube to pass through to the die and the remaining flange or ring is removed from the die with the outward movement of the punch and the ring is then stripped from the punch.

In the accompanying drawings; Figure 1 85 is a longitudinal mid-sectional view of the die and extrusion punches showin a punch withdrawn from the die and the billet to be extruded arranged therein.

Figure 2 is a longitudinal mid-sectional view showin the extrusion punches in their position within the die at the inward end of their stroke.

Figure 3 is a longitudinal sectional view of the die showing the shearing punch in the position at the completion of its inward stroke, having sheared the tube from its flanged ends. I

Figure 4 is a longitudinal mid-sectional view of the die showing the shearing punch in its outward stroke with the stripper removing the flange ring therefrom. In carrying this invention into effect the billet 1 from which the tube is to be made is first heated to the desired temperature and is then placed within the die 2 which has arranged in the bottom thereof the throat ring 3 w 'ch is formed with a converging upper surface 4 leading to the throat 5 which is of the diameter required to-produce the desired diameter of tube.

The extrusion punch 6 is adapted to move into the upper end of the die and toe the top of t e billet and force it downwar y and the extrusion in 7 which extends through the die is a apted to be projected through the billet and into the throat to form the inner wall of the tube to be extruded.

This arrangement of extrusion tool is quite well known and it is not deemed '-v;:;: to show ,the means for operating same but it will be understood that the extrusion pin moves in advance of the extrusion punch and extends well into the throat of the die before the extrusion unch engages in pressure contact with the Eillet.

\Vhen the extrusion punch is pressed downwardly against the metal of the billet,.the metal is caused to flow downwardly over the converging surface 4 of thet-hroat ring and flow? between the wall of the throat 5 and pm When the extrusion punch has moved to its innermost position as illustrated in Figure 2 it will be seen that a flange 8 remains on the upper end of the tube 9. The punch'and extrusion pin are withdrawn in the reverse operation of the press and a iercing pin 10 is moved downwardly into t e die ln-axial relation thereto and this pin'is the same diameter as the outer diameter of the tube and in its downward movement it shears throu h the flange8, cutting a hole therethrough t e same diameter as the punch.

The metal cut from the ring in this shearing operation is a contiguouspart of the tube 9 and is forced downwardly through the throat of the die. When the metal is out completely through, the tube drops from the die, leaving the flange 11 surrounding the punch. Shrinking of the metal'causes the flange ring to grip the piercing pin so that as the pin is withdrawn from the die the rin is carried with it.

stripper 12 surrounds the piercing pin and as the pin moves upwardly and clears the die the flange ring is engaged b the stripper and is removed from the pm. uitable means (not shown may be lprovided to prevent the ring from ropping ack into the die period of the operation. a

at this It will be understood from this description that as the tube is pushed through the die its length is only limited by the capacity of the die and the qualit and temperatures of the 6 metal being extru ed and further, the o ration as described, adds to the length 0 the tube the thickness of the flange.

The method of forming tubes as herein described eliminates the necessity of a sawing 10 operation to cut the flange from the tube. It

will of course be understood that the operation of piercing the flange andclearin the tube therefrom is a separate operation 510111 the extrusion operation but is carried out on 16 a multiple die press and the extrusion of one tube is concurrent with the piercing of a previously extruded tube, that is to say, the extrusion die and piercing pin are carried on the same mm of the punch and operate toto gether, one operating in one die cavity while the other operates in another.

It will of course be understood that this method is not limited to any particular crosssectional shape of tubing and round, hexago- 85 nal and other sections may be made.

This invention is an improvement in the manufacture of tubes by extrusion and must' not be confused with the known method of forming nuts and blanks by heading a rod and 80 then shearing the rod from the upset. metal,

which process has been known and in common operation for a number of years.

What I claim as my invention is:

A means for forming tubes by extrusion,

8 comprising a die having a constricted open bottom, an extrusion punch adapted to close the top of the die and to extrude a metal billet through the constricted opening in the bottom, an extrusion pin of less diameter ex- 0 tending through said punch into said opening, a piercing pin 0 the same transverse dimensions as the constricted opening in the die adapted to enter the die upon the removal of the extruding punch and to shear the tube 5 from the flange remaining on its upper end, and a stripper adapted to remove the flange ring from the piercing pin on its outward movement from the die.

JOHN WYCLIFFE LEIGHTON. 

